3 Answers
3

It's not exactly built for ESX and it's not on the HCL but it should be fine, to find out if it's VT-X capable contact Dell first and ask then if it's 'Windows 7 Virtual XP mode compatible' (which is the same thing but is less likely to confuse them) - get their any response in writing.

First, I am a very happy Dell customer and nothing more: My personal experience with Dell Sales is that they do not know processor specs at this level. I would not trust them, as I did once when I purchased the only Core 2 Quad Intel makes that doesn't support VT - and, yes, the sales guy said that it did. Buyer beware.
– condiosluzverdeJan 18 '10 at 17:53

I agree, so long as you get it in writing you're covered.
– Chopper3Jan 18 '10 at 18:07

the SPEC code warning means thhat there are motherboards that will not support VT even though the chip will. It would not in the least bit suprise me if dell's motherboard does not support VT. Dell is notrious for disabling parts they don't deem required by a desktop OS. (the disabling of core i7 turbo mode on the studio XPS line is the latest example that comes to mind). If you're set on dell make sure you can return it without paying a fee if it's not up to spec. Chopper suggestes getting their response in writing which might help but with dell is no guarantee of their compliance,

However, there are 2 different processors, one with VT one without.
You need the one with the part number ending in ML (See note above the table there).

I would do my best to try to cross reference whatever numbers you can find and/or some feature that Dell lists (perhaps a CPU speed or something).

It's a bit of a gamble.

On the bright side, if you have the time etc (and please confirm with Dell yourself) - they usually have a 21-day return for full refund policy, where they pay the shipping.
I've done that in the past with no problems at all. So, you could get the machine and check the BIOS when you boot it - if no VT, then return it.

See Jim B's answer below also: great information. Again, I have found the most important assurance is that you can return without having to pay shipping, etc. as Jim below said.
– condiosluzverdeJan 18 '10 at 18:03